Device for sterilizing a forced air flow by means of ultraviolet radiations

Abstract

A device for sterilizing a forced air flow by means of ultraviolet radiations, comprising an elongated housing provided with reflecting inner surfaces accomodating at least an ultraviolet radiations source and a fan for sucking air into the device and sending it out after being subjected to the ultraviolet radiation in an air flow passage. The device provides at each ends means for shielding and absorbing the ultraviolet radiation to prevent the dispersion thereof outside the device, made up by an optical labyrinth formed by parallel and spaced fins. In an embodiment to be applied to an air conditioning plant, the device does not include a fan and the input opening is shaped for being fitted the output of an air conditioning duct.

I claim: 
     
       1. A device for sterilising a forced air flow by means of ultraviolet radiations comprising: a housing having input and output openings for the air and provided with reflecting inner surfaces;   a low pressure mercury vapor lamp located inside said housing; and   an optical labyrinth with a plurality of parallel and spaced sheets defining paths for the air flow and shielding and absorbing the ultraviolet radiation to prevent the escaping thereof outside the device.   
     
     
       2. A device as claimed in claim 1, wherein said sheets are angled fins shaped as a much opened V. 
     
     
       3. A device as claimed in claim 1, wherein said sheets are in form of undulated wave-like sheets. 
     
     
       4. A device as claimed in claims 1 to 3, wherein said housing is elongated and provides for a tangential fan with a protection grid for sucking air into the device and sending it outside after being subjected to an ultraviolet radiation in a flow passage. 
     
     
       5. A device as claimed in claim 4, wherein the axis of said at least one mercury vapor lamp is aligned with the direction of the air flow. 
     
     
       6. A device as claimed in claim 5 further providing for an output radiused wall having a non-reflecting surface and an output grid. 
     
     
       7. A device as claimed in claims 1 to 3 wherein said input opening is adapted for fitting the outlet of an air conditioning plant, and said optical labyrinth is located on the output side of the device. 
     
     
       8. A device as claimed in claim 7 wherein the axis of said at least one mercury vapor lamp is transversely disposed with respect to the direction of the air flow. 
     
     
       9. A device as claimed in claim 1 wherein said input opening is adapted to be fitted to the outlet of an air conditioning plant, and said shielding and absorbing means comprises an optical labyrinth with a plurality of angled fins, parallel and spaced in respect to each other, at the output end of the device.